Total confusion?!!!

I had my medical abortion April 25, 2019 so almost 2 months ago. I was wondering how long it took/takes for hcg levels to get back down to zero? I had my blood drawn yesterday and the doctor called me today saying that my hcg levels are still up (she didn’t tell me what the number was) but the pregnancy test i took 2 days ago was negative. I’m trying to figure out if I’m pregnant again or if my levels haven’t gone down from the procedure. Has anyone else experienced this?